/** * Check if a cache response satisfies a request's caching constraints * * @param RequestInterface $request Request to validate * @param Response $response Response to validate * * @return bool */ public function canResponseSatisfyRequest(RequestInterface $request, Response $response) { $responseAge = $response->calculateAge(); $reqc = $request->getHeader('Cache-Control'); $resc = $response->getHeader('Cache-Control'); // Check the request's max-age header against the age of the response if ($reqc && $reqc->hasDirective('max-age') && $responseAge > $reqc->getDirective('max-age')) { return false; } // Check the response's max-age header if ($response->isFresh() === false) { $maxStale = $reqc ? $reqc->getDirective('max-stale') : null; if (null !== $maxStale) { if ($maxStale !== true && $response->getFreshness() < -1 * $maxStale) { return false; } } elseif ($resc && $resc->hasDirective('max-age') && $responseAge > $resc->getDirective('max-age')) { return false; } } if ($this->revalidation->shouldRevalidate($request, $response)) { try { return $this->revalidation->revalidate($request, $response); } catch (CurlException $e) { $request->getParams()->set('cache.hit', 'error'); return $this->canResponseSatisfyFailedRequest($request, $response); } } return true; }